A liquid crystal display is a flat panel display most widely used currently, which has features such as a low power consumption, a small size, a low weight and a low driving voltage.
Referring to FIG. 1, FIG. 1 is a schematic diagram showing a structure of electrodes and a liquid crystal layer in a liquid crystal display panel in the related art. The liquid crystal display panel includes a first common electrode 21 disposed at a side of a liquid crystal layer 30, a plurality of pixel electrodes 11 disposed at another side of the liquid crystal layer 30, and a plurality of second common electrodes 12 arranged alternately with the pixel electrodes. When no driving voltage is applied, liquid crystal molecules in the liquid crystal layer 30 are vertical; and when a driving voltage is applied, an electric field 40 is generated between the pixel electrodes 11 and the first common electrode 21 and the second common electrodes 12, the liquid crystal molecules are rotated under action of the electric field 40 so as to achieve a display. It can be seen from FIG. 1 that when the driving voltage is applied, the liquid crystal molecules at two sides of one pixel electrode 11 are arranged at two angles, which is referred to as a two-domain structure. In a display panel having a two-domain structure, a low contrast degree and a color shift exist. Especially in case of being at an oblique viewing angle, a quality of the display image observed by a user is poor.
Referring to FIG. 2, FIG. 2 is a schematic diagram showing another structure of electrodes and a liquid crystal layer in a liquid crystal display panel in the related art. Compared with the liquid crystal display panel in FIG. 1, in this liquid crystal display panel, a dielectric layer (OC) 22 is added on the side of the second common electrode 21. The dielectric layer 22 can make horizontal equipotential lines in the electric field 40 be distributed in the dielectric layer 22 as far as possible, which can increase a proportion of vertical equipotential lines in the liquid crystal layer 30, i.e., a proportion of the horizontal electric field, thereby increasing tilt angles of the liquid crystal molecules and improving the contrast degree of the liquid crystal display panel. Compared with the liquid crystal display panel in FIG. 1, although the liquid crystal display panel in FIG. 2 has a higher contrast degree, it is still a two-domain structure, and the problem also exists that in case of being at an oblique viewing angle, the viewing angle is not ideal. It is still difficult to solve this problem in the existing technology.